Let P(E) denote the probability of the event E. Given P(A) = 1, P(B) = 1/2,…
2003
Let P(E) denote the probability of the event E. Given P(A) = 1, P(B) = 1/2, the values of P(A | B) and P(B | A) respectively are
- A.
1/4, 1/2
- B.
1/2, 1/14
- C.
1/2, 1
- D.
1, 1/2
Attempted by 5 students.
Show answer & explanation
Correct answer: D
Since P(A) = 1, event A occurs with certainty. Therefore, if B occurs, A still occurs, so P(A | B) = 1. Also, P(B | A) = P(B intersection A)/P(A). Because A is certain, B intersection A is just B, so P(B | A) = P(B)/1 = 1/2. Hence the required values are 1 and 1/2 respectively.